How to change the battery in BMW key

Here's a detailed step-by-step guide in English on how to change the battery in a BMW key fob (for most models with a removable battery, like the diamond-shaped or rectangular fobs):

🔧 How to Change the Battery in a BMW Key Fob

Step 1: Determine your key type
BMW has different key types. The most common types with replaceable batteries are:

• Rectangular Key Fob (used in many F-series models)

• Diamond-Shaped Key (common in older E-series models)

If your key has a rechargeable battery (like some E60 or 7 Series models), it cannot be replaced easily—you’d need to replace the whole key or have the battery professionally changed.

🔋 For Rectangular Key Fob (Replaceable CR2032 Battery):

1. Remove the emergency key blade
Slide the small button on the side or back of the key and pull out the mechanical key.

2. Open the key fob case
Use a small flathead screwdriver or a coin to pry open the key fob along the seam. Be gentle to avoid damaging the plastic.

3. Remove the old battery
Take out the old CR2032 battery using your tool. Remember the battery orientation (positive side usually faces up).

4. Insert the new battery
Insert a new CR2032 battery with the positive (+) side facing up.

5. Snap the key fob back together
Align the two halves of the key fob and press them together until they click.

6. Reinsert the emergency key blade

🔋 For Diamond-Shaped BMW Key (Older Models):

These keys usually have a rechargeable battery soldered to the circuit board, charged through the ignition. If your diamond key no longer works:

• You cannot replace the battery easily without special tools and soldering.

• Either buy a new key from BMW or find a professional who can replace the battery.

✅ Tips:

• Always use high-quality branded batteries (like Panasonic or Energizer) for long life.

• If the key still doesn’t work after battery replacement, recheck the orientation or try resynchronizing it to the car.

• Dispose of the old battery properly.